Let's say you want to know which of your clients are behind on their payments.
You can head into your Reports section and select the Customer Aging Report.
This report will first give you a quick summary of how many of your payments are past due by how long they're past due.
Next, this report will break down all of your contacts that have due balances.
You will see a subtotal for each time window (0-30 days past due, 31-60, etc) with a Total Past Due (total amount that is due according to your payment policies on signed contracts), and Total Outstanding (the total amount owed by a client including both past and future payments, such as a Net 30 payment that may not be 'due' now).
Now that you know the amounts due in each time frame, you can hover over that amount to get quick access to the projects with outstanding balances.